The data transmission network is developing towards the direction that there are more and more nodes and the topology is increasingly complicated. The mesh network has already become the process that will be gone through certainly in the development of the network, such as the Optical Transport Network (abbreviated as the OTN), the Packet Transport Network (abbreviated as the PTN), the Synchronous Digital Hierarchy (abbreviated as the SDH), etc. And in the traditional SDH, the Wavelength Division Multiplexing (abbreviated as the WDM) and the OTN network, it can only generally provide the following protection method to the network survivability: link 1+1 protection, M:N protection, ring sharing protection and intelligent mesh network recovery through the control plane, and these protection methods all have the corresponding protection protocols.
These schemes all have a typical shortcoming, for example, the link 1+1 protection has the data transmission on both the working path and the protection path of the protection group, and it is an exclusive protection method, wherein the utilization rate of the network resource is very low, the maximum utilization rate is 50%, and usually it can only be up to 40%. The protection path of the M:N protection and the ring sharing protection can be shared, wherein the ring sharing protection is the sharing of the path topology in the ring topology, but the maximum utilization rate of its network resource can only be up to 50%; the resource utilization rate of the M:N protection is very high, but the protected link and the source and destination nodes of the protection link are required to be coincident, which restricts the flexibility of the configuration, and one special case of the M:N protection is the 1:1 protection; the intelligent Mesh recovery is that the available resource is calculated dynamically by the control plane after the service is damaged, and the resource utilization rate is higher and can exceed 50%, but the time of the intelligent Mesh recovery is usually in one hundred millisecond grade, which is unable to meet the requirement of 50 milliseconds in the transmission field.
FIG. 1 shows a typical network topology of the Mesh, and the nodes (indicated as the APS node in the figure) with the function of the Automatic Protection Switching (abbreviated as APS) connect with each other through a plurality of paths. If the protection resource is reserved in the links of the whole network as the sharing protection path, as shown in FIG. 2, the protection path is indicated by the P-path in the figure, then the method for sharing protection will be unusually complicated on one hand, and on the other hand, the resource utilization rate of the network can only be up to 50%.